Radius turning attachment



March 29, 1949. QBAD|AH RADIfis TURNING ATTACHMENT 2 Sheets-Sheet 1 Filed Sept. 17, 1945 l N VEN TOR.

March 29, 1949. .L. E. OBADIAH 2,465,393

RADIUS TURNING ATTACHMENT Filed Sept. 17, 1945 2 Sheets-Sheet 2 IN VEN TOR.

zem'm EOAQJ/b/I fi/Torney Patented Mar. 29, 1949 rslcs Claims.

(Granted under the act of March 3, 1883, as amended Aprii 30, 1928; 3'70 0; G. 757') This invention relates to Iathes, and more particularly to a radius turning attachment for latices.-

The object of the invention is to provide an attachment for iathes which may be easily attached to any standard lathes, and when attached serves for the cutting of tores or radii on the work piece, either at the end, convex or concave, or along the side of the work piece. This attachment, complete in itself, may, by means of adaptors, be secured to the cross slide of a lathe, after the usual. standard parts have been removed the cross slide. attachment is self-contained and may be readily at tached to and taken off the lathe.

This invention comprises a self-contained radius turning attachment for lathes similar turning machine tools, having a housing over a bearing plate or a disc with a recess on its bottom, adjusting screws in said housing entering said recess, a turntable having a center coincident with the center of said recess, means for rotating the turntable, a toolholder on said turntable foradjustably supportin a too-l having its point centered in relation to said turntahle' center, said attachment being adapted to be detachably attached to a standard cross-slide of a lathe centered to centerline of the headstock and. tailstockof the lathe.

The invention consists further in the combi nation of such an attachment with adaptors, one aring shaped adaptor to surround a post of the conventional cross-slide, and one a conical adaptor to engage a recess of a cross-slide, either adaptor being used depending on whether the cross-slide has a post or a recess.

Screws or other suitable securing means are provided on the attachment to engage the adaptor to secure the adaptor to the attachment, and the attachment to the post of the cross-slide, and in the case of the conical adaptor, screws or other securing means are provided to secure the adaptor to the attachment, and other screws or securing means are provided to secure the conical adaptor to the cross-slide.

The invention consists further in a precision instrument in which the turntable is provided with a degree scale and the housing with a pointer indicating the degree of circular movement of the tool point, and in which the tool support has linear graduated means indicating the amount of radial movement of the tool point from its centering position in either direction, which amount of movement in one or the other direction determines the radius of the arc of circular movement of the cutting point of the tool, whereby the attachment may function fdr either convex or concave cutting of the end of the work piece, or toric cutting laterally of the work piece.

The invention will be further described, an em bodiment thereofshown in the drawings, and the invention will be finally pointed out in the claims.

In the accompanyin drawings,

Fig. l a side view of a conventional lathe,- with the improved attachment applied thereto;

Fig. 2 is a plahvie'w of the attachment;

Fig. 3 is a transverse vertical section on line B -30f Fig. 2;

Fig.- 4 is a transverse vertical section on line i -4 of 2;

Fig. 5 is a fragmentary plan View, with parts broken away;

Fig. 6 is a horizontal section on line Fig, 4;v

Fig; '7 is a crosssection of across-slide having a recess", and showing a conical adaptor connected therewith,- and with the bottom-ofthe attachment;

Fig; 8 is a cross section of across-slide having, a posit and showing a rin adaptor connected therewith; and with the bottom of the attachmerit; v

Figs. 9' and 1 0 are; diagrammatic views; Fig. 9 in plan and Fig. 1-0 in sideview, showing the tool point centering to the headstock and tailstockcenter line; v

Fig. 11 is a diagrammatic plan view of a work piece, and the different cutting positions of the tool, in convex cutting;

Fig. 1-2 is-a diagrammatic plan View 6f a work piece, and the difierent positions of the tool, in

concave cutting;

Figs. 13 and 14 is a central section and plan view, respectively, of a ring adaptor;

Figs. 15 and 16 is a side View and pl-an View, respectively. of a conical adaptor,- and Fig. 17 is a diagrammatic plan view of a work" piece, and the difierentpositions of the tool. in

toric cutting.

Similar characters of reference indicate corresponding parts throughout the v'arious views:

Referring to the drawings a knownor con-ventional lathe' is shown in Fig. 1, showing the improved attachment applied thereto.

As known, the tailstock Id has aspindlemovable long-itudinally by ahand'wheel 12 The work piece support i3 is rotatedby known means I4. The cross-slide 16- supporting the known compound rest and tool holder is movable longitudinally along the bed of the lathe by the hand wheel l8. The cross-slide I6 is movable transversely to the longitudinal line of the lathe by a handle [9. The cross-slide I6 may have either a recess or a post as known, to which the compound rest and toolholder support is connected. The compound rest is removed leaving the known cross-slide l6 either with a recess such as |1A (Fig. '7), or a cross-slide l6 with a post such as H (Fig. 8), depending on the type of the lathe.

The attachment itself, indicated generally by 39 as seen in Fig. 2, consists of a housing 3|, having a recess 32 (Fig. into which a worm screw 33 fits, one end 34 of the screw fitting into the bearing 35, and the shaft 35A, and held in place by a screw bushing 35B and extending outside of the housing 3| and having a handwheel 36. Seated within the housing 3| is a non-rotatable bearing plate or disc 61, having a recess 38 at its lower side, and a central shoulder 39 at its upper side. The axes of the shoulder portion 39 and recess 38 are coincident. The bearing plate 31 and the housing 3| are secured together by screws 31A. This shoulder portion has a bore which is screwthreaded to engage the screw 4|, the head of which holds down a washer 42 against the shoulder portion 39. Between the extending part of the washer 42 and the bearing plate 31 a peripheral worm gear 44 is provided which rides on the surface 49 of the bearing plate 31 and against the shoulder portion 39 and engages the worm 33. Oil grooves 31B are provided. The gear 44 has secured to it a rotatable disc or turntable 43 by means of four screws 46. The upper surface of this turntable 43 is provided with circumferentially arranged degree markings 41, visible also through a pointer 48, as shown in Fig. 2, which pointer 48 is secured to the housing 3|.

Upon the turntable 43, there is secured a tool holder generally indicated by 59 (Figs. 2, 3, and 4). This tool holder 59 consists of a base 5| resting on the turntable 49. The base 5| has a screwthreaded bore 52, which is engaged by a dial screw 53 having a knurled end 54. On this dial screw 53 there is a dial 55 having a circular graduated portion on its periphery, each line indicating a thousandths of an inch rotation. The knurled end 54 and the dial 55 are spaced from each other to allow a dial bracket 56 to support the dial screw 53, the bracket 56 being secured to the turntable 43 by the screws 51. A pointer 55A points towards the markings on the dial 55 to indicate the reading. The base 5| moves over a dovetail slide 58, having a gib 59, for adjustment purposes, and tightened or loosened by set screws 59a. The slide 58 is secured to the turntable 43 by screws 58A.

As seen in Figs. 3 and 4, the base 5| has a tool post 5|, which has exterior screwthreads to engage a rotatable adjusting screwthread ring 62, upon which the tool 69 rests. The tool post 6| is slotted to permit the passage of the tool 69. The top 63 of the tool post 6| has a screwthreaded bore engaged by a screw 64, with a bolt head 64A. By raising or lowering the ring 62, and correspondingly the screw 64, the tool 69 may be raised or lowered. Also the tool 69 may be moved axially, until clamped in operative position by the screw 64.

The base 5| has a pointer 9| extending therefrom, which extends over the zero position on the radius scale 92 shown in Fig. 2. To either side of the zero linear graduated markings are arranged. These graduations are in fractions of an inch, but it is understood that any type of linear calibration or Vernier scale could be used. When the tool 69 is in normal position, the pointer 9| is on zero. When the tool 69 is moved in either direction, by the base 5| moving over the slide 58, by the turning of the end 54 of the screw 53, the pointer 9| shows the amount of movement. This amount of movement is indicative of the length of the radius of the circle through which the cutting edge 99 of the tool 69 passes, the circle having its center coincident with the center point 89 of the attachment.

As illustrated in Fig. 4, at the lower side of the bearing plate 31, diagrammatically opposed screws 65 are provided which pass through the housing 3|, and through the bearing plate 31, and have their free ends enter the recess 38. This recess 38 is made sufiiciently large in diameter, to be larger than any diameter of a post H as used on standard lathes. These screws 65 are shown as engaging the upper conical portion 26A of the conical adaptor 26, which is shown in dotted lines in Fig. 4. The lower part 26B of the conical adaptor 26 fits into a recess 1A of the cross-slide I6 as shown in Fig. 7. This conical adaptor 26 is shown in detail in Figs. 15 and 16. A collar 260 is disposed between the conical portions 26A and 26B, and the lower surf-ace of this collar 26C rests on the cross-slide I6. It will be noted that the lower surfaces of the bearing plate 31 and the housing 3|, rest upon the upper surface of the cross-slide I6. The ends of the screws 65 engage between the upper conical portion 26A and the collar 26C.

The adaptor 26 is held in position on the crossslide l6 by a screw 69 as shown in Fig. 7, which screw engages the lower conical surface 263 of the adaptor 26, and between it, and a, collar 26D WhlCh has the same diameter as the recess |1A,

as shown in Fig. 7. The collars 26D and 26E have the same diameter.

If the cross-slide I6 has a post 1 as known and shown in Fig. 8, then a ring adaptor 25 as shown in Figs. 13 and 14, is employed, and the screws 65 are passed through screwthreaded portions 253 and are tightened against the post I1. It may be noted that the bore 25A of the adaptor 25 snugly fits against the upper part of the post l1. Thereby the attachment 39 is operatively secured to the cross-slide iii of the lathe when the cross-slide |6 has a post I1.

In Figs. 4, 6, '7 and 8 these screws 65 are shown parallel with the line of the shaft A, but in practice it is preferred to have them at as in many lathes, adjustment is simpler when the screws are at 45.

In Fig. 9, which is a plan view, the headstock 19 is aligned with the tailstock 1|. The work piece 12 is secured in support |3 accordingly. The face 13 of the tool 69 is aligned with the headstock 10, tailstock 1|, center line 14, but the axial center line 15 of the tool 69 is spaced 5'; of an inch from the line 14, the width of the tool 69 being 1% of an inch, so as to use the full length of the tool 69 and obtain a maximum of 99 on a shown in Fig. 3, and the height of the cutting edge 90 is in line with the headstock 1B tailstock H longitudinal center line 14, all as diagrammatically shown in Figs. 9 and 10. The pointer 9| is over the zero position of the radius scale 92, and the pointer 55A is on the zero reading of the dial 55.

By turning the handle 35, the turntable 43 may be moved in either direction, and the tool cutting edge 95 moves in a circle. By turning the knob 54, the tool 69 may be moved forwardly or rearwardly.

When the dial screw 53 is rotated clockwise, the cutting edge 90 of the tool 69 is brought back to the right side of the center line 8%] for convex cutting; and by turning the dial screw 53 counter clockwise, the cutting edge $.16 is advanced to the left side of the center line t9 and concave cutting is made possible. The size of the radius (convex or concave) is indicated by the pointer 99 over the radii scale 92, and the pointer 55A over the dial 55, both starting from zero in either directicn.

In order to cut the work piece l2 into an exterior convex curved surface, the body of the work piece 12 to be cut is placed over and beyond the dead center point SE] of the attachment 3% as shown in Fig. 11. The distance from the center point 88 to the final end cutting arc is the radius of the final cutting, and this is noted on the radius scale 92 on the right side of zero. The work piece 12 is rotated clockwise in the direction of the arrow 8! as seen in Fig. 11, looking in the direction from the headstock Hi to the tailstock 'H. The tool cutting edge 9t is moved in an arc 82, which, as seen, cuts the corner of the work piece 12. The hande 36 is rotated and the tool iii) is moved clockwise, the cutting action of the tool fit on the work piece 72 being in the clockwise direction upon and from the axis of the work piece 12 radially outwards. The rotation of the work piece i2 clockwise as shown by the arrow 8i during the cutting action of the tool 6i) resulting in the convex spherically shaped end of the work piece 12. The tool 60 is returned to its initial position by the rotating of the handle 36 in counterclockwise direction. The attachment 3! is then moved longitudinally 74 on the lathe by rotating the handle 13, and this brings the tool 66 to the second dot-dash line position 82A shown in Fig. 11, and the center 36 or the attachment 39 is thereby moved to A. The handle 36 is then rotated and the tool cutting edge 98 is moved in an arc and cuts off the work piece 12 along the next arc 82A shown in second dot-dash line in Fig. 11. The tool 69 is then brought back, and the attachment is again advanced by turning the handle it, so that the center point 89 of the attachment 3!! takes the position 80B. The handle 36 is turned and the work piece 12 out along arc 82B. These arcs are shown only as examples. In practice, the skilled operator makes many more cuttings, until the desired shape has been attained.

If it is desired to enlarge the convex spherical cutting, this can be carried out by continuing the rotation of the turntable 43 until the markings of about 170 (or complete 340) register with the pointer 48, a supporting stem on the work piece 12 being necessary to be maintained.

If it is desired at the end of the 90 operation,

to cut the work piece i2 axially, the entire attachment 30 is shifted by the operation of the lathe hand wheel 58, and the ordinary cylindrical cutting. is carried out without moving the turnt'able 43.

In order to cut the work piece 12 into an. interior concave curved surface, as seen diagrammatically in Fig. 12, the tool cutting edge 90 is moved to the left of the center 80. The control by the radius scale 92 is carried out as heretofore described, but on the left side of the zero. The work piece 12 is now rotated counter clockwise, as shown by the arrow 83, and the cutting edge 99 of the tool 60 follows the cutting are 82. The movement of the turntable 43 is now counter clockwise, starting with 90 reading on pointer 48, during the cutting action of the tool 60. The cutting action is in the direction of the curved arrows shown which arrows begin at the edge 90 in Fig. 12; and this cutting action thrust of the edge 99 ends at the axis of the work piece 12. As the work piece i2 is rotating, a concave cut is ob ained, as shown by the extensions beyond the arrow heads in Fig. 12. The cutting edge 90 after it has reached the longitudinal axis 74 of the work piece 72 is moved back out of the concavity already formed, by rotating the turntable 43 clockwise, the tool til having a pivot point at 8B in Fig. 12. Thus, when are 82 has been cut, the

' tool Ell is returned to its initial position, and the attachment 38 is moved by the handle it until the center point 803 arrives at A. Then the handle 35 is rotated to turn the turntable 43 counterclockwise, and the arc 82A is cut. The tool 63 is then brought back to its initial position. The center point is shifted from 88A to 8GB, and the arc 82B is cut. Again a skilled operator will repeat these actions until the cutting is completed as desired. It will be noted that for a concave radius cutting not more than a 90 quadrant or a total of 180 concave hemisphere can be cut.

The operation is as follows:

The known tool holder and compound rest of the lathe is removed leaving the cross-slide IS with its post ll or recess l'iA exposed. This post ll or recess HA is then centered in l ne with the headstock 'iil, tailstock i l, longitudinal center line it, as well known.

The attachment 3!] is secured to the crossslide 55 as previously described. The turntable scale 4i is moved so that the zero degree is readable through the pointer 48; the zero reading on the radius scale 92 is registered with the pointer ill; and the zero reading on the dial 55 is registered with the pointer 55A. The cutting edge 90 of the tool fit is now placed in the longitudinal axial line It as shown in Fig. 9, and the height of the tool til is adjusted by moving adjusting ring 52 and screw 64A up or down until cutting edge 90 is co ncident with the center line .14 in Fig. 10. It might be noted here that the maximum diameter capacity of this attachment is double the height of the center line i in Fig. 10 to the top of the turntable 43, this height varying on different lathes.

Referring to Fig. 11, the tool 60 is moved to the full line position and it with its point 90 is rotated by the handle 36 from its full line position, to chip ofi the portion 82. The rotation of the work piece 72 is clockwise as shown by the arrow 8i, and'the cutting edge 95 of the tool 60 is at the right side of the center Bil. The progressive cuttings are made as described until the cutting has been completed.

The same general operation takes place when a concave cutting is desired, as shown in Fig. 12, only the rotation is counterclockwise as shown by the arrow 83, and the tool cutting edge 95] is on the left side of the center line 80.

The attachment 30 is also capable of being used for turning toric surfaces laterally of the longitudinal axis 14 of the work piece 12. For turning such a toric surface, one first turns a cylindrical portion 95 on the work piece 12 in the known manner, the work piece i2 rotating clockwise in the direction of the arrow 84 as seen in Fig. 1'7. The turntable 43 is now rotated from the zero position shown in Fig. 2, to a position where 90 shows on the pointer 458. The radius scale pointer 9| is placed on the right side of the scale 92 to indicate the radius to be cut. The tool 60 is then moved. to the position shown in full line in Fig. 17.

The handle IQ of the lathe is then rotated in order to move the entire attachment 3B, transversely to the longitudinal line '54 or the lathe, along the line 71.

Now, by rotating the handle 36 alternately in a clockwise and counterclockwise manner, the work piece 12 is chipped off along the arc, and the tool 60 is intermittingly advanced, and cuttings made along the arcs 82 82A and 823, while the center 88 is moved to 80A and 80B respectively, until the cutting coincides with the perimeter point 91A, which is on the original or initial line 95. The toric surface is then completed in accordance with the desired curvature or size. The points MA and 80 are in a plane 71 transverse to the longitudinal axis 74 of the work piece 12, and the ends 93 and 93A of the tore are in a plane 94 parallel with the axis of the work piece 12. In Fig. 17, the cutting extends beyond the point 93A, in order to indicate the possibility of extending the circular out if desired.

It may be further added that it is possible to turn an inside toric surface by the use of a C- shaped offset tool, the procedure being a combination of convex toric turning and concave radii turning.

The improved attachment 30 difiers from the prior art in that the said attachment 36 has the bottom recess 38, the center of which is the controlling center for the turntable 43 and to which the cutting edge 90 of the tool M is centered. The tool 60 being on the turntable (i3 is under the control of the scale 41. The tool Bil is also under the control of the dial screw 53 and radii scale 92, and thereby is a precision instrument. The improved attachment 341 is seli-contained. When the desired radius turning has been completed, the self-contained attachment 30 is removed from the lathe, and put away until it is again desired to be used, the lathe being then used for its usual purposes.

Though the attachment 30 may be used for other purposes, it is especially useful for preparing convex or concave gauges, dies, laps, cutting tools, or form tools on any material or plastic, etc., where radii are required, or used for.

The attachment 3% may, if desired, be used on a lathe to take the place of the known compound, for regular work, with the only limitation under the present construction being the limited travel of the tool as compared to the present compound. Any known shaped tool, threading or cutting, can be used.

I have described several forms of my invention, but obviously various changes may be made in the details disclosed without departing from the spirit of the invention as set out in the following claims.

The invention described herein may be manuiactured and used by or for the Government of 53 the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

Iclaim:

1. In a self-contained radius turning attachment for lathes, the combination with a housing having a recess in its bottom, adjusting screws in said housing entering said recess, a turntable for said housing having a center coincident with the center of said recess, means for rotating the turntable, and a tool holder on said turntable for adjustably supporting a toolbit centered in relation to said turntable center, said housing being adapted to be detachably attached to a standard cross-slide of a lathe centered to the centerline of the headstock and tailstock of the lathe, a ring-shaped adaptor engaging said recess of the housing, and engaged by said screws, said screws engaging a post on said cross-slide, when said attachment has been applied to the crossslide.

2. In a self-contained radius turning attachment for lathes, the combination with a housing having a recess in its bottom, adjusting screws in said housing entering said recess, a turntable for said housing having a center coincident with the center of said recess, means for rotating the turntable, and a tool holder on said turntable for adjustably supporting a toolbit centered in relation to said turntable center, said housing being adapted to be detachably attached to a standard cross-slide of a lathe centered to the center line of the headstock and tailstock of the lathe, a conical shaped adaptor engaging said 4' recess of the housing, said screws engaging the conical surface of the adaptor, said adaptor engaging also a recess on the cross-slide, when the attachment is applied to the cross-slide, and screws on the cross-slide engaging the conical adaptor for holding the adaptor to the crossslide.

3. In a radius turning attachment for lathes, the combination of a housing, a disc within the housing having a circular recess in its bottom, a worm gear for said disc, a worm for the worm gear, a turntable movable with the disc, and having a scale, a pointer on the housing, a tool support-on the turntable, means determining the position of the tool point when a tool is in said support, means indicating the position of the tool point in respect to the center of the disc, and an adaptor for said recess in said disc, said adaptor being adapted to secure the attachment to the cross-slide of the lathe.

4. In a radius turning attachment for lathes, the combination of a housing, a disc within the housing having a circular recess in its bottom, a worm gear for said disc, a worm for the worm gear, a turntable movable with the disc, and having a scale, a pointer on the housing to indicate the amount of turning of the turntable from a zero position, a tool support on the turntable, means determining the position of the tool point when a tool is in said support, said means including increment indications showing the amount of movement, means indicating the position of the tool point in respect to the center of the disc, and an adaptor for said recess in said disc, said adaptor being adapted to secure the attachment to the cross-slide of the lathe.

5. In a radius turning attachment for lathes, the combination of a housing, a disc within the housing having a circular recess in its bottom, a worm gear for said disc, a worm for the worm gear, a turntable movable with the disc, and

having a scale, a pointer on the housing to indicate the amount of turning of the turntable from a zero position, a tool support on the turntable, means determining the position of the .tool point when a tool is in said support, said means including increment indications showing the amount of movement, means indicating the position of the too] point in respect to the centerof the disc, an adaptor for said recess in said disc, said adaptor being adapted to secure the attachment to the cross-slide of the lathe, and means turning an inside toric surface combining convex toric turning and concave radius turning. LEONARD E. OBADIAH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

